This invention relates to a method of and apparatus for closing bags, more particularly to a method of and apparatus for closing the tops of open-mouth bags packed in boxes or cases.
The invention is especially directed to a method of and apparatus for closing the tops of bags serving as liners in rectangular boxes or cases which have top closure flaps hinged to the four sides, the top portion of the bag in the case being turned inside out (everted) and cuffed down on the outside of the flaps, the bag or liner having been filled with product and the flaps extending tip at the four sides. The method involves uncuffing the bag, i.e. turning its cuffed top portion outside in so that it extends upwardly from the case, gathering the upwardly extending top portion, and then closing the latter, as by taping, the apparatus being operable to carry out the method, and the method and apparatus involving improvements on the method and apparatus shown in U.S. Pat. Nos. 4,813,207 and 4,912,913.
The method and apparatus shown in said U.S. patents are generally limited to handling square cases, and a principal object of the present invention is to provide an improved method and apparatus capable of handling rectangular cases other than square cases, i.e. cases having four sides, two opposite sides of which are shorter than the other two, the shorter sides being referred to as the ends of the case, and for handling cases of different sizes. Generally, the cases have what are referred to as major closure flaps hinged to the upper edges of the two sides (the long sides) of the case, and what are referred to as minor closure flaps hinged to the upper edges of the ends of the case, these flaps being closed down on top of the case after the bag or liner therein has had its top formed into a neck and the neck closed, as by taping it, and the neck tucked down into the case.
In general, the method of this invention involves closing the top of a bag containing product in a rectangular case having two opposite sides and two opposite ends and side closure flaps and end closure flaps hinged to the top of the sides and ends, respectively, the flaps extending up at the sides and ends, the top of the bag being turned down inside out on the outside of the f laps forming a cuff. The method comprises conveying cases with the bags therein in a predetermined path one after another to an uncuffing station and holding each case at said station, uncuffing the bag and disposing the top of the bag to extend upward above the closure flaps with the top having portions extending up at the sides of the case and portions extending up at the ends of the case, and with the bag mouth open, and bringing the side portions of the top together to flatten the top generally in a vertical plane lying generally centrally between the sides of the case. The case is then conveyed farther forward in said path with the flattened top portion moving forward endwise generally in said plane, the flattened top portion is compacted endwise to form it into a neck for the bag, and a closure is applied to the neck to hold it compacted.
In general, apparatus of this invention comprises means for conveying cases with the bags therein in a predetermined path one after another to an uncuffing station and holding each case at said station, means at said uncuffing station for uncuffing the bag and disposing the top of the bag to extend upward above the closure flaps with the top having portions extending up at the sides of the case and portions extending up at the ends of the case, and with the bag mouth open, and means for bringing the side portions of the top together to flatten the top generally in a vertical plane lying generally centrally between the sides of the case. The conveyor is then operable to convey the case farther forward in said path with the flattened top portion moving forward endwise generally in said plane. The apparatus further comprises means for compacting said flattened top portion endwise to form it into a neck for the bag; and means for applying a closure to the neck to hold it closed.
Other objects and features will be in part apparent and in part pointed out hereinafter.